/*
 * Copyright 2015-2025 the original author or authors.
 *
 * All rights reserved. This program and the accompanying materials are
 * made available under the terms of the Eclipse Public License v2.0 which
 * accompanies this distribution and is available at
 *
 * https://www.eclipse.org/legal/epl-v20.html
 */

package org.junit.jupiter.api;

import static java.util.stream.Collectors.joining;

import java.util.Deque;
import java.util.function.Supplier;

import org.jspecify.annotations.Nullable;
import org.junit.platform.commons.annotation.Contract;
import org.junit.platform.commons.util.UnrecoverableExceptions;
import org.opentest4j.AssertionFailedError;

/**
 * {@code AssertionUtils} is a collection of utility methods that are common to
 * all assertion implementations.
 *
 * @since 5.0
 */
class AssertionUtils {

	private AssertionUtils() {
		/* no-op */
	}

	@Contract(" -> fail")
	static void fail() {
		throw new AssertionFailedError();
	}

	@Contract("_ -> fail")
	static void fail(@Nullable String message) {
		throw new AssertionFailedError(message);
	}

	@Contract("_, _ -> fail")
	static void fail(@Nullable String message, @Nullable Throwable cause) {
		throw new AssertionFailedError(message, cause);
	}

	@Contract("_ -> fail")
	static void fail(@Nullable Throwable cause) {
		throw new AssertionFailedError(null, cause);
	}

	@Contract("_ -> fail")
	static void fail(Supplier<@Nullable String> messageSupplier) {
		throw new AssertionFailedError(nullSafeGet(messageSupplier));
	}

	static @Nullable String nullSafeGet(@Nullable Supplier<@Nullable String> messageSupplier) {
		return (messageSupplier != null ? messageSupplier.get() : null);
	}

	static String getCanonicalName(Class<?> clazz) {
		try {
			String canonicalName = clazz.getCanonicalName();
			return (canonicalName != null ? canonicalName : clazz.getTypeName());
		}
		catch (Throwable t) {
			UnrecoverableExceptions.rethrowIfUnrecoverable(t);
			return clazz.getTypeName();
		}
	}

	static String formatIndexes(@Nullable Deque<Integer> indexes) {
		if (indexes == null || indexes.isEmpty()) {
			return "";
		}
		String indexesString = indexes.stream().map(Object::toString).collect(joining("][", "[", "]"));
		return " at index " + indexesString;
	}

	static boolean floatsAreEqual(float value1, float value2, float delta) {
		assertValidDelta(delta);
		return floatsAreEqual(value1, value2) || Math.abs(value1 - value2) <= delta;
	}

	static void assertValidDelta(float delta) {
		if (Float.isNaN(delta) || delta < 0.0) {
			failIllegalDelta(String.valueOf(delta));
		}
	}

	static void assertValidDelta(double delta) {
		if (Double.isNaN(delta) || delta < 0.0) {
			failIllegalDelta(String.valueOf(delta));
		}
	}

	static boolean floatsAreEqual(float value1, float value2) {
		return Float.floatToIntBits(value1) == Float.floatToIntBits(value2);
	}

	static boolean doublesAreEqual(double value1, double value2, double delta) {
		assertValidDelta(delta);
		return doublesAreEqual(value1, value2) || Math.abs(value1 - value2) <= delta;
	}

	static boolean doublesAreEqual(double value1, double value2) {
		return Double.doubleToLongBits(value1) == Double.doubleToLongBits(value2);
	}

	static boolean objectsAreEqual(@Nullable Object obj1, @Nullable Object obj2) {
		if (obj1 == null) {
			return (obj2 == null);
		}
		return obj1.equals(obj2);
	}

	private static void failIllegalDelta(String delta) {
		fail("positive delta expected but was: <" + delta + ">");
	}

}
